I admittedly know nothing about what formal contracts or agreements might exist between the band and Jeff's widow. If there are no agreements the band is clearly breaching, then she can fuck right off.
The fact of the matter is that Jeff had to have, or should have had, at least a decent bit of money by the time he died. Did he have no life insurance at all? I'm sure I make less than Jeff at his peak and I have plenty of life insurance to ensure my family, two kids included, would be fine if I dropped over tomorrow. And he's been dead for 27 years. There are no young kids to worry about supporting, she presumably has plenty of time. She can get off her ass and support herself. Really a shame after all the band has done for Jeff. I'm sure he'd be beside himself if he were here.